1. Field of the Invention
The present invention relates to a fuel injection controlling apparatus for an internal combustion engine, and particularly to a technology for controlling a fuel injection timing in starting an internal combustion engine.
2. Description of the Related Art
In an internal combustion engine such as a gasoline engine or the like, a fuel injection controlling apparatus for determining a fuel injection timing or a fuel injection amount (fuel injection period) in response to an operational condition of the engine.
An apparatus for performing a fuel injection before opening an intake valve in starting the internal combustion engine, using a so-called intake non-synchronous injection system is known as such a fuel injection controlling apparatus.
By the way, since it is difficult to gasify the fuel at an extremely low temperature and it is likely that the fuel would adhere to a wall surface or the like, in the case where the intake non-synchronous injection type fuel injection controlling apparatus starts the internal combustion engine at an extremely low temperature, it is necessary to inject a large amount of fuel exceeding an amount of fuel to be adhered to an intake port or the like in advance. Namely, since the injection fuel is to be adhered to the intake port or the like, the intake non-synchronous injection type fuel injection controlling apparatus cannot form a combustible mixture within a combustion chamber unless a large amount of fuel is injected.
In order to solve such a problem, a fuel injection apparatus for an internal combustion engine disclosed in Japanese Patent Application Laid-open No. Sho 62-210230. This fuel injection apparatus is provided with a start timing detecting means for detecting a start timing of the engine, a temperature detecting means for detecting a temperature of the engine, and a means for performing the fuel injection in an intake stroke when it is detected by the above-described start timing detecting means and the above-described temperature detecting means that the engine is started under the condition of the temperature that is lower than a predetermined temperature, and is an intake synchronous injection type fuel injection apparatus for injecting fuel in synchronism with a valve opening timing of an intake valve of each cylinder.
In such an apparatus, since the fuel injection is performed in synchronism with the valve opening timing of the intake valve in starting the internal combustion engine, it is possible to feed a major portion of the fuel injected from the fuel injection valve directly into the combustion chamber. As a result, in the intake synchronous type fuel injection apparatus, it is possible to form a combustible mixture in the vicinity of the ignition plug at the fuel injection amount less than that of the intake non-synchronous injection type fuel injection apparatus.